Activation of β-adrenergic receptor signaling prevents glucocorticoid-induced obesity and adipose tissue dysfunction in male mice.

Elevated serum concentrations of glucocorticoids (GCs) result in excessive lipid accumulation in white adipose tissue (WAT) as well as dysfunction of thermogenic brown adipose tissue (BAT), ultimately leading to the development of obesity and metabolic disease. Here, we hypothesized that activation of the sympathetic nervous system either via cold exposure or the use of a selective β3-adrenergic receptor (β3-AR) agonist alleviates the adverse metabolic effects of chronic GC exposure in rodents. To this end, male 10-wk-old C57BL/6NRj mice were treated with corticosterone via drinking water or placebo for 4 wk while being maintained at 29°C (thermoneutrality), 22°C (room temperature), or 13°C (cold temperature); in a follow-up study mice received a selective β3-AR agonist or placebo with and without corticosterone while being maintained at room temperature.

Targeting TGF-β for treatment of osteogenesis imperfecta.

BACKGROUNDCurrently, there is no disease-specific therapy for osteogenesis imperfecta (OI). Preclinical studies demonstrate that excessive TGF-β signaling is a pathogenic mechanism in OI. Here, we evaluated TGF-β signaling in children with OI and conducted a phase I clinical trial of TGF-β inhibition in adults with OI.

COPB2 loss of function causes a coatopathy with osteoporosis and developmental delay.

Coatomer complexes function in the sorting and trafficking of proteins between subcellular organelles. Pathogenic variants in coatomer subunits or associated factors have been reported in multi-systemic disorders, i.e.

A global Slc7a7 knockout mouse model demonstrates characteristic phenotypes of human lysinuric protein intolerance.

Lysinuric protein intolerance (LPI) is an inborn error of cationic amino acid (arginine, lysine, ornithine) transport caused by biallelic pathogenic variants in SLC7A7, which encodes the light subunit of the y+LAT1 transporter. Treatments for the complications of LPI, including growth failure, renal disease, pulmonary alveolar proteinosis, autoimmune disorders and osteoporosis, are limited. Given the early lethality of the only published global Slc7a7 knockout mouse model, a viable animal model to investigate global SLC7A7 deficiency is needed.

Identification of Functionally Distinct Mx1+αSMA+ Periosteal Skeletal Stem Cells.

The periosteum is critical for bone maintenance and healing. However, the in vivo identity and specific regulatory mechanisms of adult periosteum-resident skeletal stem cells are unknown. Here, we report animal models that selectively and durably label postnatal Mx1+αSMA+ periosteal stem cells (P-SSCs) and establish that P-SSCs are a long-term repopulating, functionally distinct SSC subset responsible for lifelong generation of periosteal osteoblasts.

A multicenter study to evaluate pulmonary function in osteogenesis imperfecta.

Pulmonary complications are a significant cause for morbidity and mortality in osteogenesis imperfecta (OI). However, to date, there have been few studies that have systematically evaluated pulmonary function in individuals with OI. We analyzed spirometry measurements, including forced vital capacity (FVC) and forced expiratory volume in the first second (FEV ), in a large cohort of individuals with OI (n = 217) enrolled in a multicenter, observational study.

TGF-β Family Signaling in Mesenchymal Differentiation.

Mesenchymal stem cells (MSCs) can differentiate into several lineages during development and also contribute to tissue homeostasis and regeneration, although the requirements for both may be distinct. MSC lineage commitment and progression in differentiation are regulated by members of the transforming growth factor-β (TGF-β) family. This review focuses on the roles of TGF-β family signaling in mesenchymal lineage commitment and differentiation into osteoblasts, chondrocytes, myoblasts, adipocytes, and tenocytes.

Osteointegration and Resorption of Intravertebral and Extravertebral Calcium Phosphate Cement.

Study Design: Eleven patients with painful osteoporotic vertebral fractures who underwent kyphoplasty using calcium phosphate (CaP) cement were followed up for 1 week, 1, 2, and 3 years in a monocentric, nonrandomized, noncontrolled retrospective trial.

Objective: This study investigates long-term radiomorphologic features of intraosseous CaP cement implants and of extraosseous CaP cement leakages for up to 3 years after implantation by kyphoplasty.

Summary Of Background Data: Kyphoplasty is frequently used for the treatment of painful osteoporotic fractures.

Genetic causes and mechanisms of Osteogenesis Imperfecta.

Osteogenesis Imperfecta (OI) is a genetic disorder characterized by various clinical features including bone deformities, low bone mass, brittle bones, and connective tissue manifestations. The predominant cause of OI is due to mutations in the two genes that encode type I collagen. However, recent advances in sequencing technology has led to the discovery of novel genes that are implicated in recessive and dominant OI.

Fkbp10 Deletion in Osteoblasts Leads to Qualitative Defects in Bone.

Osteogenesis imperfecta (OI), also known as brittle bone disease, displays a spectrum of clinical severity from mild (OI type I) to severe early lethality (OI type II), with clinical features including low bone mass, fractures, and deformities. Mutations in the FK506 Binding Protein 10 (FKBP10), gene encoding the 65-kDa protein FKBP65, cause a recessive form of OI and Bruck syndrome, the latter being characterized by joint contractures in addition to low bone mass. We previously showed that Fkbp10 expression is limited to bone, tendon, and ligaments in postnatal tissues.

Pharmacological and biological therapeutic strategies for osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a connective tissue disorder characterized by bone fragility, low bone mass, and bone deformities. The majority of cases are caused by autosomal dominant pathogenic variants in the COL1A1 and COL1A2 genes that encode type I collagen, the major component of the bone matrix. The remaining cases are caused by autosomal recessively or dominantly inherited mutations in genes that are involved in the post-translational modification of type I collagen, act as type I collagen chaperones, or are members of the signaling pathways that regulate bone homeostasis.

Correlations Between Bone Mechanical Properties and Bone Composition Parameters in Mouse Models of Dominant and Recessive Osteogenesis Imperfecta and the Response to Anti-TGF-β Treatment.

Osteogenesis imperfecta (OI) is a group of genetic disorders characterized by brittle bones that are prone to fracture. Although previous studies in animal models investigated the mechanical properties and material composition of OI bone, little work has been conducted to statistically correlate these parameters to identify key compositional contributors to the impaired bone mechanical behaviors in OI. Further, although increased TGF-β signaling has been demonstrated as a contributing mechanism to the bone pathology in OI models, the relationship between mechanical properties and bone composition after anti-TGF-β treatment in OI has not been studied.

Sclerostin Antibody Treatment Improves the Bone Phenotype of Crtap(-/-) Mice, a Model of Recessive Osteogenesis Imperfecta.

Osteogenesis imperfecta (OI) is characterized by low bone mass, poor bone quality, and fractures. Standard treatment for OI patients is limited to bisphosphonates, which only incompletely correct the bone phenotype, and seem to be less effective in adults. Sclerostin-neutralizing antibodies (Scl-Ab) have been shown to be beneficial in animal models of osteoporosis, and dominant OI resulting from mutations in the genes encoding type I collagen.

Excessive transforming growth factor-β signaling is a common mechanism in osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a heritable disorder, in both a dominant and recessive manner, of connective tissue characterized by brittle bones, fractures and extraskeletal manifestations. How structural mutations of type I collagen (dominant OI) or of its post-translational modification machinery (recessive OI) can cause abnormal quality and quantity of bone is poorly understood. Notably, the clinical overlap between dominant and recessive forms of OI suggests common molecular pathomechanisms.

Differential effects of collagen prolyl 3-hydroxylation on skeletal tissues.

Mutations in the genes encoding cartilage associated protein (CRTAP) and prolyl 3-hydroxylase 1 (P3H1 encoded by LEPRE1) were the first identified causes of recessive Osteogenesis Imperfecta (OI). These proteins, together with cyclophilin B (encoded by PPIB), form a complex that 3-hydroxylates a single proline residue on the α1(I) chain (Pro986) and has cis/trans isomerase (PPIase) activity essential for proper collagen folding. Recent data suggest that prolyl 3-hydroxylation of Pro986 is not required for the structural stability of collagen; however, the absence of this post-translational modification may disrupt protein-protein interactions integral for proper collagen folding and lead to collagen over-modification.

Strontium enhances osseointegration of calcium phosphate cement: a histomorphometric pilot study in ovariectomized rats.

Background: Calcium phosphate cements are used frequently in orthopedic and dental surgeries. Strontium-containing drugs serve as systemic osteoblast-activating medication in various clinical settings promoting mechanical stability of the osteoporotic bone.

Methods: Strontium-containing calcium phosphate cement (SPC) and calcium phosphate cement (CPC) were compared regarding their local and systemic effects on bone tissue in a standard animal model for osteoporotic bone.

E-selectin ligand 1 regulates bone remodeling by limiting bioactive TGF-β in the bone microenvironment.

TGF-β is abundantly produced in the skeletal system and plays a crucial role in skeletal homeostasis. E-selectin ligand-1 (ESL-1), a Golgi apparatus-localized protein, acts as a negative regulator of TGF-β bioavailability by attenuating maturation of pro-TGF-β during cartilage homeostasis. However, whether regulation of intracellular TGF-β maturation by ESL-1 is also crucial during bone homeostasis has not been well defined.

Identical LDL-cholesterol lowering but non-identical effects on NF-κB activity: High dose simvastatin vs combination therapy with ezetimibe.

Objective: Lowering LDL-cholesterol by statins has been proven to be associated with reduction of proinflammatory regulators e.g. activation of the transcription factor NF-κB.

Kyphoplasty in patients with multiple myeloma a retrospective comparative pilot study.

Background: This retrospective study of 73 myeloma patients with painful vertebral lesions compares clinical and radiomorphological outcomes up to 2 years after additional kyphoplasty, radiation therapy or systemic treatment only.

Methods: We assessed pain, disability and radiomorphological parameters by visual analogue scale (VAS 0-100), Oswestry Disability Index and by re-evaluating available follow-up X-rays, respectively, in patients that were treated according to a clinical pathway.

Results: After 2 years the VAS score was reduced in all groups by 66 ± 8.

Mutations in SERPINF1 cause osteogenesis imperfecta type VI.

Osteogenesis imperfecta (OI) is a spectrum of genetic disorders characterized by bone fragility. It is caused by dominant mutations affecting the synthesis and/or structure of type I procollagen or by recessively inherited mutations in genes responsible for the posttranslational processing/trafficking of type I procollagen. Recessive OI type VI is unique among OI types in that it is characterized by an increased amount of unmineralized osteoid, thereby suggesting a distinct disease mechanism.

Osteoplastic procedures for the treatment of vertebral complications in multiple myeloma patients.

Pain induced by vertebral fracture in multiple myeloma can be treated by an osteoplastic procedure. The magnitude of the pain reduction by the procedure depends on the presence of additional causes for pain as spondylosis deformans, osteochondrosis, stenosis of the spinal canal, or intervertebral nerve compression. To identify additional reasons for pain apart from a vertebral fracture-induced pain, a detailed preoperative analysis of the patients complaints is crucial for the outcome after an osteoplastic procedure.

Three-year outcomes after kyphoplasty in patients with osteoporosis with painful vertebral fractures.

Purpose: Kyphoplasty immediately improves pain and mobility in patients with painful osteoporotic vertebral fractures, but long-term clinical outcomes are still unclear. This controlled trial evaluates pain, mobility and fracture incidence 3 years after kyphoplasty.

Materials And Methods: Kyphoplasty was performed in 40 patients with painful osteoporotic vertebral fractures; 20 patients who were selected for kyphoplasty but chose not to undergo the procedure served as controls.

Direct effects of osteoprotegerin on human bone cell metabolism.

Purpose: Osteoprotegerin (OPG) affects bone metabolism by intercepting the RANK-RANKL interaction which prevents osteoclastic differentiation and consequently reduces bone resorption. Different bone phenotypes of mice overexpressing OPG and of mice with knockdown of receptor activator of NF-kappaB (RANK) or RANK-ligand (RANKL) suggest that the mechanism of action of the OPG-RANKL-RANK system in regulating bone remodeling is not completely understood. Furthermore, OPG increases bone mass and density independently from reduced osteoclastogenesis which is consistent with the possibility that OPG may directly affect bone metabolism beyond its known role as decoy receptor for RANKL.

Transient post-operative thyrotoxicosis after parathyroidectomy.

Background: Secondary and tertiary hyperparathyroidism are features of chronic renal disease. Although pharmacological options are available, parathyroid surgery remains the treatment of choice in these patients with worsening renal osteodystrophy or hypercalcemia. The development of thyrotoxicosis after parathyroid surgery in these patients has been rarely reported.

Calcium-phosphate and polymethylmethacrylate cement in long-term outcome after kyphoplasty of painful osteoporotic vertebral fractures.

Study Design: A comparative prospective trial evaluating 3-year outcome.

Objective: To compare clinical and morphologic outcomes as well as follow-up fractures after kyphoplasty of painful osteoporotic vertebral fractures with calcium-phosphate (CaP) cement (group 1) and with polymethylmethacrylate (PMMA)-cement (group 2).

Summary Of Background Data: CaP cements seem to be an alternative material for usage in kyphoplasty of vertebral fractures.